The RNase A ribonuclease gene family has been a source of information on unusual evolutionary constraints and their effects on protein structure and function at the molecular level. While RNase A ribonucleases maintain invariant disulfide bonds and catalytic components that are necessary for RNA degradation, there has been a large amount of divergence in other regions. As such, the specific patterns of diversification have been best understood among the RNase A ribonucleases of mammalian species. To date, divergence patterns among the non-mammalian RNase A ribonucleases have not been as clearly defined.
The RNase A ribonucleases have been implicated in a wide variety of physiologic functions, including angiogenesis, cellular apoptosis, and anti-tumor and anti-pathogen host defense via a complex array of seemingly unrelated molecular mechanisms; however still, the physiologic activities of many of the RNase A ribonucleases remain unexplored. This is also true of many of the mammalian RNase A ribonucleases. Some of the RNase A ribonucleases have been observed to promote angiogenesis. Angiogenic activity may be important in, for example, wound healing or tissue repair. Clinically, ulcers associated with diabetes or burn wounds that are caused by impaired blood supply, may be amenable to treatment with therapeutic angiogenic promoters. Thus, it would be desirable to promote angiogenesis in these conditions, and the activities of RNase A ribonucleases or peptide fragments could prove useful to that end.
The RNase A ribonucleases have been observed to be involved in anti-pathogen host defense. Antibiotics are a common therapy for the treatment or prevention of bacterial infection; however increasingly more bacteria are becoming resistant to conventional antibiotic therapy. Thus, a need in the art remains for new anti-bacterial agents. Accordingly, a greater understanding of the RNase A ribonuclease gene family, its functional domains, and its role in angiogenesis and anti-pathogen host defense may provide novel therapeutic agents.